Understanding Retaining Walls 

Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides.

Before you build any retaining walls, you’ll need to know several things. You’ll have to understand the properties of the soil, the slope in the elevation of the ground. You also have to factor into the height that the wall is going to have to be built at. These factors will help with the design and construction of the wall. There are different types of walls such as masonry block walls, concrete walls, poured concrete walls, sheet pile walls, and so on. In some cases, you may have to speak to a professional such as a geologist or a soil engineer you want to ensure that you were using the proper type of retaining wall for the soil type. You also need to make sure that the retaining wall itself is designed within the standard engineering practice for that type of wall.

Retaining Wall Types

Retaining walls can be billed for both commercial landscaping as well as residential areas. The landscape of a property can be transformed by a retaining wall as well as prevent additional soil erosion. Here are the four types of retaining walls that are usually constructed. The individual situation will determine what type of wall you’re going to build.

Gravity Retaining Wall

Gravity Retaining Wall

This type of wall has mass, so it resists the soil pressure from behind the wall. If you have a small landscaping project, this is the ideal type of wall. It should be considered the most basic type of retaining wall but it has plenty of applications. It is variable in terms of the materials that you can use to build this sort of wall.

These walls depend on their mass to resist pressure from behind and are good for short landscaping walls. Gravity retaining walls are the most basic, as they allow for the widest amount of variety when it comes to materials.

Cantilevered Retaining Wall

Cantilevered Retaining Wall

One of the most basic types of retaining walls is the cantilevered retaining wall. It is useful in applications where there is medium to a large height. This wall is usually made out of concrete. The stem, which is the wall itself, is anchored to a concrete footing. This resists the weight of the soil and prevents the wall from tipping over. To achieve maximum strength of the wall, it is reinforced with steel rebar.

Sheet Piling Retaining Wall

Sheet Piling Retaining Wall

When you have a tight space or soft soil, you usually use a sheet piling retaining wall. This is a thin wall of wood, steel, or vinyl. It is driven directly into the soil. There is usually a vertically corrugated structure that helps reinforce the wall.

Anchored Retaining Wall

Anchored Retaining Wall

When you expect to have a higher load or when the wall is thinner, you can build an anchored retaining wall. This wall allows for different fronts, which are supported by anchors that are driven into the soil. These will be attached by straps or cables.  this is done to provide more support for the wall.


The type of material you use to build your retaining wall will all depend upon your needs. It’s best to speak to a professional about your individual situation to determine the best type of material for your retaining wall.

  • Concrete – Many walls are made out of concrete because it is durable.
  • Stones, rocks, boulders – Rocks stones and boulders are often used because they are given an aesthetically pleasing look to the wall. This can be ideal for a residential wall. The downside to these materials is that there are more costs involved.
  • Wood or treated timber – Using wood or treated timber can be used to build a wall, but it’s more susceptible to decay and often has to be replaced within several years.
  • Masonry Blocks – Masonry blocks are used because they don’t require a lot of maintenance, and there are many colors as well as sizing options available.

Do I need an Engineer?

Many municipalities will require a design plan as well as a permit to build some walls depending upon the height of it. You’ll have to get this from a structural engineer if the wall is over 4 feet high. If you have a T-wall, you also need a permit and a design from an engineer. If there is a slope at the top of the retaining wall, then you may also need an engineer to examine it. If you are moving soil around a civil engineer will have to examine the grading plan and to ensure that the soil is drained properly. It’s best to speak to a planner or professional prior to building your wall to ensure that you are following all the proper rules and procedures.


Whenever you redesign some parts of your home, you usually need a permit. This is the case when you do alterations, additions, or any new construction. When you want to build a retaining wall, you may need a plan from an engineer to ensure that the project is done in the correct way.


Sometimes when you may not have to get a permit. You’ll have to check with your individual jurisdiction to see what the proper rules and regulations are. If you have never designed a wall before, you should speak to an engineer to ensure that the wall is being constructed in the proper way. In any case, you should speak to professionals before you design or build any wall for your property.

Permit Types

The codes, regulations, and zoning rules of the area that you live in will determine the type of permit that you’re going to need. Factors such as the type of structure and the impact on the environment will also come into consideration. Cities have certain zoning laws about the length in the size of the wall. This is based on the property line and the size of the home. You will need to call local officials and speak to them. They may ask you several questions. By using a licensed engineer, you’ll ensure that you’re following the codes of your jurisdiction. They can also help you design and plan your retaining wall. There are several factors that usually require a permit which is as follows:

  • Your wall will exceed four feet in the total height. This is from the bottom of the footing of the wall to the top of your retaining wall
  • If you have a back slope that is adjacent to your retaining wall
  • There are any surcharge load conditions that exist. This includes roads, buildings, sloped conditions, or vehicle loads
  • If there are solid fences which are attached or adjacent to the area where you wish to build

Speak to an Expert

You have many things to consider before you build any retaining wall. You should speak to professionals about the wall before you design or build one. It is critical to speak to professionals in your local jurisdiction to ensure that your following all the rules and regulations that pertain to the building of the wall.